1. Field of the Invention
The invention relates to an ESD protection device, and more particularly to an SCR-based ESD protection device.
2. Description of the Related Art
Electrostatic discharge (ESD) damage has become one of the main reliability concerns facing integrated circuit (IC) products. Particularly, when scaled down to the deep sub-micron regine, integrated circuits become more vulnerable to ESD stress. Semiconductor controlled rectifier (SCR) devices had been used as an ESD protection device to protect complementary metal oxide semiconductor (CMOS) integrated circuit against damage. The SCR devices have the advantage of low holding voltage, which results in less power dissipation in the SCR devices under the ESD event than other ESD protection devices, such as thin oxide NMOS, or diode, in the CMOS technologies. Thus, the SCR devices can sustain much higher ESD voltage with a smaller layout area.
MOS transistors and SCR devices are both efficient protection devices, however, the MOS transistors are widely used in the industry. This is because the SCR device used for an ESD protection in deep submicron CMOS technologies has the latch-up issue.
Thus, it is desired to provide a novel SCR device structure with lath-up free to protect integrated circuits in low operating voltage application.